Childhood brain tumor survivors experience neurocognitive declines that may impact the family system. Research with other illness populations (e.g., traumatic brain injury) illustrates the potential of neurocognitive functioning and family functioning to affect each other. The primary goals of this application are to examine the concurrent relations between survivor neurocognitive functioning and family functioning (Aim 1) and the prospective influences of family functioning (Aim 2) and medical treatment intensity (Aim 3) on survivor neurocognitive functioning. The proposed research is the first known study to investigate prospectively these interrelations in childhood brain tumor survivors (N = 50) and their caregivers. Participants will include those treated with either cranial or cranial-spinal radiation and transitioning off of active medical treatment. Participants will complete a brief battery of neuropsychological tests assessing all areas where childhood brain tumor survivors generally show deficits (working memory, processing speed, verbal memory and executive function) at the conclusion of medical treatment (T1) and again 6 months later (T2). Caregivers also will complete well-validated measures of quality of life and family functioning at both time points. Twenty-five participants with Time 2 data also will repeat these measures 1 year post-treatment (T3). It is hypothesized that (1 & 2) better family functioning will be positively associated with concurrent survivor neurocognitive functioning and survivor and caregiver quality of life at T2 and (3) better family functioning at T1 will be associated with fewer decline in survivor neurocognitive functioning at T2. It also is hypothesized (4) that greater treatment intensity will be associated with greater decline in survivor neurocognitive functioning. Exploratory analyses will examine whether family functioning at T1 moderates the relation between treatment intensity and decline in neurocognitive functioning seen at T2. Findings from this study could inform clinical care with childhood brain tumor patients and subsequent research among a broader group of survivors affected by central nervous system disease. Data from this study will be used for future grant submissions and will serve as the basis for a programmatic line of research that examines psychosocial influences on the neurocognitive late effects experienced by childhood cancer survivors.